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METALLURGY OF CAST IRON.
should be devoted for this special work and there should be a place for every tool and all kept as neat and clean as possible.
After a mould has been rammed up, by the author's system, the round portion of the test bar pattern is then pulled out endwise, before the cope is lifted off, as seen in Fig. 128, this page. For a handle to draw out the test bars endwise, two inches of the patterns project outside of the flask as shown at H. The cope is then lifted off and the balance of the pattern and gates drawn out.
After all loose H F
sand or dirt has been blown out lightly with a pair of bellows, the cope is closed on, flask clamped, and then up-ended ready for casting, as seen in Fig. 130, on page 527.
In drawing out the test bar patterns endwise, give them a half-twist around the mould before starting to pull the pattern straight out and they will come very easily, as it only requires a pull of from eight to twelve pounds at the moment of greatest power to draw them out. The pattern should be kept well varnished or bees-waxed, so as to prevent the friction of the sand wearing them away by a few years' use or cause them to becoir e rough, making a 'k dirty mould.'' When the chills at A, Fig. 120, and V V, Fig. 126, pages 509 and 522, are used, care should always be taken that they